The Illinois House on Tuesday voted 61-54 to approve same-sex marriage, setting up the state to become the 15th to allow gay marriages.

Supporters said they had the 60 votes needed to make same-sex marriage legal as of June 1, 2014, after support from House Speaker Mike Madigan pointed to the long-awaited vote finally taking place.

The bill that passed the Senate this year had an effective date of Jan. 1 and required 71 votes, but Rep. Greg Harris changed the date to June 1 to require only 60 votes. SB10 must now go back to the Senate for another vote before Gov. Pat Quinn signs it, a move he already said he supports.

"It feels kind of obvious," Rep. Ann Williams said during the debate leading up to the vote. "Why wouldn't we treat everyone the same?"

Rep. Thomas Morrison urged a no vote during the debate to "protect the institution of marriage" and "strengthen and protect real marriage." Rep. Jeanne Ives called it "the worst bill in the country."

The vote comes after supporters of gay marriage rallied at the state capitol to encourage House leaders to approve the measure after a disappointing spring session.

The measure initially failed to pass the Illinois House when the regular session ended in May. It was approved by the state's Senate on Valentine's Day, but a lack of votes kept it stalled in the House. The bill has been supported by Mayor Rahm Emanuel, Quinn, Sen. Mark Kirk and President Barack Obama who exhorted legislators during a Chicago visit to approve the measure.

"Here in Illinois, we've got a vote on same-sex marriage that's going to be coming up in the state Legislature," Obama said, "and I just want to say for the record it's something that I deeply support."

The previous week former President Bill Clinton issued a statement in support of the Religious Freedom and Marriage Fairness Act, asking legislators to stand up for the "proposition that all citizens should be treated equally under the law." Clinton joined a chorus of voices, including Republican Sen. Mark Kirk, who publicly backed the legislation earlier this year.

Clinton said he believed the vote would strengthen the country, putting it closer to the nation's mission of forming a "more perfect union."

A divided Supreme Court this summer struck down the federal Defense of Marriage Act as unconstitutional, a move supporters hoped would help lawmakers' decision in Illinois.

“Members of the Illinois House now have more than 1,100 new reasons to make marriage equality the law in Illinois," Quinn said after the DOMA vote.

"This decision should strengthen our commitment in the State of Illinois toward ensuring that the life-long commitments of all Americans are honored and respected by the law," Emanuel said. "The state should not be standing in the way of two people loving each other."